Victor Chew

Beautiful and clean build .

Kevin, Looks interesting. Any chance this will be available in pcb form in the near future?

That's a piece is historical treasure. What tubes is the amp using?

Looks really nice Emooze.

Thanks Kerry. If I do get my hands of either of the headphones will certainly post my impression again.

Thanks John. The presentation to me for both these amps (KGSShv with 007 vs Dynahi with HD580) are different and it would be difficult to say which is better. I guess it boils down to a matter of taste. Personally, I still prefer the music out of the electrostatic rig. The dynahi is no slouch and it is probably the best I have heard for any dynamic headphone amplifier by a substantial margin. The Dynahi puts the listener closer to the musicians than the Stax. It is fast, exciting and engaging. I find myself tapping to the music most instantly. I am not really a bass head but this thing gives out bass that is tight, authoritative and voluminous. The sense of space around the instruments and vocalist makes them clearly identifiable. As such, clarity must be the biggest strength of this design. Treble is extended but lacks the "airiness" of the Stax. As for the midrange I can feel the realism and emotions of the singer. It has everything the Stax rig has but I just prefer the way the stax presents it. Others may feel otherwise . My impression is based on the HD580 and may be different with different headphones. Oh yes, one other thing, I feel it is really powerful. Its like when you step on the car accelerator and the power never seems to puncture. I know I am bad a describing music, so please do forgive me.

Thanks Cal. Come over and have a listen to it.

Thanks Pars. Manually, I was able to get it to about +-3mv for the dc offset. Patience was the key. With insertion of the opamps the dc offset achieved 0mv. Was also able to get balance to 0mv.

Picture of my almost completed Dynahi. Top plates still have to be painted and lacquered. It sounds lovely. Thank you Kevin for this lovely design.

Congratulations Cal. Where did you get the PSU case from? I may be headed that way as well.

How much time delay would be recommended? Would 10 seconds be enough? Just to clarify, we change the 2k in the PSU to 1k? Do we still leave out the 2N3904?

For amp I made rough adjustments to about 200mV DC before slotting in the opamp. After which I got about 20 to 40 mV DC. Will be removing the regulators and using opa445 later.

Typo. Its mV DC.

Just got my offboard dynahi to work. Had some initial teething problems with the PSU. It's working nicely now. To get it to work properly, I had remove the dual track and 6 limiters. Had to also repair the cut track under the board by jumpering from the 24v zener to the 2k resistor. To get the amp DC voltage down I adjusted one of the outside 10k CCW and the other CW. With 7812, 7912 and opa27gp was able to get DC offset between 20mA to 40mA. No music yet as input, output, ground wires and hardware yet to be sorted out. I will post pictures when more is done. For me, this is more work and more challenging than either of my KGSShv builds. Also, it runs quite hot as well. Amp side is about 62C and PSU about 52C at the heatsinks. Much hotter at the L brackets. Hoping the temperature will be lower after feet are installed and drilling of ventilation holes. What kind of ground configurations are you guys using?

Congratulations Shipsupt.

Contact Lil Knight. Amongst other boards, the group buy for the T2 is on at this moment.

Awesome Kerry.

What transformers specs are you using nopants?

Can you share the change in the sound impressions?

That's beautiful. Will you be making extra decorative tube rings? I might be interested in using them for the megatron build if it fits.

It has been mentioned previously that the megatron draws more current than the KGSShv psu can supply. The concern perhaps is that if we tap it for the 300v, the draw on the current shortage will be further added.

Any substantial difference in the sound with the current turned back down?

Is your KGSShv in standard configuration or was current turned up?

John, I think I see 2 issues here. Firstly, whether you need to ground the PAS/Amp to transformer box and second, if not through the umbilical via another route. As regards first issue, my KGSShv offbaord is built in the same manner as your BH, Transformer in one box and PSU/amp in another. I connected earth ground to the amp/psu chassis as well, via the umbilical. Reasons why I did so is because, apart from the safety issues, DC offset was higher (prior to grounding to transformer box) and was oscillating a fair bit and I was also getting some noise. After the grounding (to transformer box star ground), DC offset was stable with little oscillation and the amp was dead quiet when volume was at max, of course, without input signal. As regards second issue, my onboard, also in 2 boxes, I use a separate ground wire and connect them to chassis screws. Not very nice looking and would have been much neater to use the analogue type female ground jacks.

Nice work Kerry. Looking forward to seeing the finished product.